1. Field of the Invention
The invention relates to an electronic device which radiates heat generated by a heat generating element outside a case.
2. Description of the Related Art
The case structured to radiate the heat generated by the heat generating element in the case and the heat sink have been well known. The heat sink having the structure with increased volume or surface area, or the flat structure having the surface in contact with the case further brought into tight contact therewith so as to improve the radiating effect has been known.
Japanese Patent Application Publication No. 2004-349560 discloses the electronic device with cooling system having heat generating components thermally connected to the inner surface of the wall of the case for forming the electronic device, and vent holes formed in the wall of the case around the heat generating components.
Japanese Patent Application Publication No. 2001-291806 discloses the process for radiating heat of the CPU in the laptop personal computer to the outside through the heat sink having one end attached to the surface of the CPU. The heat sink has parallely arranged plural grooves for radiation along the heat generation direction.
The electronic device with cooling system disclosed in the former patent document has the vent holes formed on the bottom of the case. The air (heat) warmed by the heat generating component rises, which is likely to be remained inside the electronic device with cooling system. The air warmed by the heat generating component is not directly radiated outside the device, which is likely to cause the heat to be remained inside the device.
In the latter patent document, the heat of the CPU disposed at the center of the laptop personal computer is radiated through the opening formed in the outer wall of the personal computer with the metal plate (heat sink) extending in the lateral direction. With the aforementioned structure, however, the air warmed by the CPU is not directly radiated outside the device, which is likely to cause the heat to be remained inside the personal computer. As the laptop personal computer has been demanded to be thin (2 to 3 cm thick, for example) by the user, the use of the heat sink for connecting the CPU and the opening of the outer wall of the personal computer may be appropriate. The above disclosed structure may cause the heat to be remained inside the device having the thickness exceeding 3 cm, for example.